Rich Stumble When Cruising

[1984rampage]

Working with turbonator LM version 13 2.5L.. When steady cruising my AFR's usually toggle between 14.5:1 - 15.0:1, but every 30 seconds to a minute the AFR's will drop to 10:1 and the car will misfire slightly and then the AFR's will go back to normal.

Does anyone else experience this or have any ideas on how to fix it? It doesnt really effect driveability that much, but it is certainly annoying.

Thanks

[GLHNSLHT2]

any codes? I wonder how close you are to exceeding the fuel trim percentage.

[1984rampage]

No codes. Been messing with the fueling tables a little, which seemed to have helped a little bit

[black86glhs]

Apparently that rich guy you mention doesn't have any game if he is stumbling while out cruisin. Needs to go hang out at the clubs.

[wallace]

I had a similar issue with my van but it was rain related. I never did figure out what was causing it. The wideband would go very rich when it occurred so it did appear to be fueling related. If I would mat it to the floor it would clear up and run good but back off the throttle and it would do it again.

[contraption22]

Could be an ignition misfire.
Try a spare HEP.

[1984rampage]

After driving more today the rich miss is only around 9"-16" of vacuum. Any more or less than that and there's no miss and the car cruises at 14.6:1-15.0:1

[1984rampage]

Would a bad coolant temp sensor cause this? I just pulled the codes and have code 22

[contraption22]

Would a bad coolant temp sensor cause this? I just pulled the codes and have code 22

Possible.